Aluminum based lewis acid cocatalysts for olefin polymerization

ABSTRACT

This invention is directed to a process for the preparation of polyolefins from one or more olefinic monomers comprising combining said olefins under olefin polymerization conditions with an organometallic catalyst compound that is activated for olefin polymerization by reaction with at least one Lewis acid aluminum compound of the formula R n  Al(ArHal) 3-n , where &#34;ArHal&#34; is a halogenated aryl group, n=1 or 2, and R is a monoanionic group other than a halogenated aryl group. The invention also relates to a polymer produced using the process and to the polymer itself.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority from Provisional U.S.application Ser. No. 60/093,017 filed Jul. 16, 1998, and is herein fullyincorporated by reference.

FIELD OF THE INVENTION

This invention relates to the preparation of olefin polymers using ioniccatalyst systems based on transition metal compounds activated by Lewisacids that are capable of providing stable polymerization catalysts.

BACKGROUND OF THE INVENTION

Group 13 based Lewis acids having three fluorinated aryl substituentsare known to be capable of activating transition metal compounds intoolefin polymerization catalysts. Trisperfluorophenylborane isdemonstrated in EP 0 425 697 and EP 0 520 732 to be capable ofabstracting a ligand for cyclopentadienyl derivatives of transitionmetals while providing a stabilizing, compatible noncoordinating anion.See also, Marks, et al, J. Am. Chem. Soc. 1991, 113, 3623-3625. The term"noncoordinating anion" is now accepted terminology in the field ofolefin polymerization, both by coordination or insertion polymerizationand carbocationic polymerization. See for example, EP 0 277 004, U.S.Pat. No. 5,198,401, and Baird, Michael C., et al, J. Am. Chem. Soc.1994, 116, 6435-6436, and U.S. Pat. No. 5,668,324. The noncoordinatinganions are described to function as electronic stabilizing cocatalysts,or counterions, for cationic metallocene complexes which are active forolefin polymerization. The term noncoordinating anion as used hereinapplies both to truly noncoordinating anions and coordinating anionsthat are at most weakly coordinated to the cationic complex so as to belabile to replacement by olefinically or acetylenically unsaturatedmonomers at the insertion site. The synthesis of Group 13-basedcompounds derived from trisperfluorophenylborane are described in EP 0694 548. These Group 13-based compounds are said to be represented bythe formula M(C₆ F₅)₃ and are prepared by reacting thetrisperfluorophenylborane with dialkyl or trialkyl Group 13-basedcompounds at a molar ratio of "basically 1:1" so as to avoid mixedproducts, those including the type represented by the formula M(C₆F₅)_(n) R_(3-n), where n=1 or 2. Utility for the tris-aryl aluminumcompounds in Ziegler-Natta olefin polymerization is suggested.

Perfluorophenylaluminum (toluene) has been characterized via X-raycrystallography. See, Hair, G. S., Cowley, A. H., Jones, R. A.,McBurnett, B. G.; Voigt, A., J. Am. Chem. Soc., 1999, 121, 4922. Arenecoordination to the aluminum complex demonstrates the Lewis acidity ofthe aluminum center. However, perfluorophenyl-aluminum complexes havebeen implicated as possible deactivation sources in olefinpolymerizations which utilize Trityl⁺ B(C₆ F₅)₄ ⁻ /alkylaluminumcombinations to activate the catalysts. See, Bochmann, M.; Sarsfield, M.J.; Organometallics 1998, 17, 5908. Bochmann and Sarsfield have shownthat Cp₂ ZrMe₂ reacts with Al(C₆ F₅)₃ 0.5(toluene) with transfer of theC₆ F₅ -moiety forming metallocene pentafluorophenyl complexes. Thesecomplexes were reported having very low activity compared to thecorresponding metallocene dimethyl complexes when activated with B(C₆F₅)₃ or Trityl⁺ B(C₆ F₅)₄ ⁻.

Supported non-coordinating anions derived from trisperfluorophenyl boronare described in U.S. Pat. No. 5,427,991. Trisperfluorophenyl boron isshown to be capable of reacting with coupling groups bound to silicathrough hydroxyl groups to form support bound anionic activators capableof activating transition metal catalyst compounds by protonation. U.S.Pat. No. 5,643,847 discusses the reaction of Group 13 Lewis acidcompounds with metal oxides such as silica and illustrates the reactionof trisperfluorophenyl boron with silanol groups (the hydroxyl groups ofsilicon) resulting in bound anions capable of protonating transitionmetal organometallic catalyst compounds to form catalytically activecations counter-balanced by the bound anions.

Immobilized Group IIIA Lewis acid catalysts suitable for carbocationicpolymerizations are described in U.S. Pat. No. 5,288,677. These GroupIIIA Lewis acids are said to have the general formula R_(n) MX_(3-n)where M is a Group IIIA metal, R is a monovalent hydrocarbon radicalconsisting of C₁ to C₁₂ alkyl, aryl, alkylaryl, arylalkyl and cycloalkylradicals, n=0 to 3, and X is halogen. Listed Lewis acids includealuminum trichloride, trialkyl aluminums, and alkylaluminum halides.Immobilization is accomplished by reacting these Lewis acids withhydroxyl, halide, amine, alkoxy, secondary alkyl amine, and othergroups, where the groups are structurally incorporated in a polymericchain. James C.W. Chien, Jour. Poly. Sci.: Pt A: Poly. Chem, Vol. 29,1603-1607 (1991), describes the olefin polymerization utility ofmethylalumoxane (MAO) reacted with SiO₂ and zirconocenes and describes acovalent bonding of the aluminum atom to the silica through an oxygenatom in the surface hydroxyl groups of the silica.

In view of the above there is a continuing need for an activatingcocatalyst compound that improves the industrial economics and providesa simpler method of synthesis and preparation of suitable activatingcompounds for ionic catalyst systems. Additionally, improvements in gasphase and slurry polymerization of olefins, where supported catalystsare typically used, are sought to meet the demanding criteria ofindustrial processes.

SUMMARY OF THE INVENTION

This invention relates to a process for the preparation of polyolefinsfrom one or more olefinic monomers comprising combining the olefinicmonomers with the reaction product of i) a transition metalorganometallic catalyst compound and ii) a neutral, aluminum-based Lewisacid compound wherein the aluminum contains at least one, preferablytwo, halogenated aryl ligands and one or two additional monoanionicligands not including halogenated aryl ligands.

The invention is also directed to an ethylene copolymer having arelatively narrow molecular weight distribution with an unexpectedimprovement in melt strength as compared to equivalent density and meltindex polymers having the same melt flow ratio as expressed as I₂₁ /I₂.As a result, the polymers of this invention have better bubblestability. In particular, the invention is to an ethylene copolymerhaving a density greater than 0.900 g/cc, and a ₂₁ /I₂ in the range offrom about 15 to about 25, and a melt strength in the range of from 6 toabout 11 cN or higher. In a preferred embodiment, the polymer is made ina gas phase polymerization process using the supported catalyst of theinvention.

DESCRIPTION OF THE INVENTION

The invention provides a process in which a Lewis acid activator and theorganometallic catalyst precursor compounds can be combined to form anactive catalyst for olefin polymerization. The invention furtherprovides for the subsequent contacting, or in situ catalyst formation,with insertion polymerizable monomers, those having accessible olefinicunsaturation, or with monomers having olefinic unsaturation capable ofcationic polymerization. The catalyst according to the invention issuitable for preparing polymers and copolymers of two or moreolefinically unsaturated monomers.

The Lewis acid compounds of the invention include those olefin catalystactivator Lewis acids based on aluminum and having at least one bulky,electron-withdrawing ancillary ligand such as the halogenated arylligands of tris(perfluorophenyl)borane or tris(perfluoronaphtyl)borane.These bulky ligands are those sufficient to allow the Lewis acids tofunction as electronically stabilizing, compatible noncoordinatinganions. Stable ionic complexes are achieved when the anions will not bea suitable ligand donor to the strongly Lewis acidic cationicorganometallic transition metal cations used in insertionpolymerization, i.e., inhibit ligand transfer that would neutralize thecations and render them inactive for polymerization. The Lewis acidsfitting this description can be described by the following formula:

    R.sub.n Al(ArHal).sub.3-n,

where R is a monoanionic ligand and ArHal is a halogenated C₆ aromaticor higher carbon number polycyclic aromatic hydrocarbon or aromatic ringassembly in which two or more rings (or fused ring systems) are joineddirectly to one another or together, and n=1 to 2, preferably n=1. Inone embodiment, at least one (ArHal) is a halogenated C₉ aromatic orhigher, preferably a fluorinated naphtyl. Suitable non-limiting Rligands include: substituted or unsubstituted C₁ to C₃₀ hydrocarbylaliphatic or aromatic groups, substituted meaning that at least onehydrogen on a carbon atom is replaced with a hydrocarbyl, halide,halocarbyl, hydrocarbyl or halocarbyl substituted organometalloid,dialkylamido, alkoxy, siloxy, aryloxy, alkysulfido, arylsulfido,alkylphosphido, alkylphosphido or other anionic substituent; fluoride;bulky alkoxides, where bulky refers to C₄ and higher number hydrocarbylgroups, e.g., up to about C₂₀, such as tert-butoxide and2,6-dimethylphenoxide, and 2,6-di(tert-butyl)phenoxide; --SR; --NR₂, and--PR₂, where each R is independently a substituted or unsubstitutedhydrocarbyl as defined above; and, C₁ to C₃₀ hydrocarbyl substitutedorganometalloid, such as trimethylsilyl. Examples of ArHal include thephenyl, napthyl and anthracenyl radicals of U.S. Pat. No. 5,198,401 andthe biphenyl radicals of WO 97/29845 when halogenated. The use of theterms halogenated or halogenation means for the purposes of thisapplication that at least one third of hydrogen atoms on carbon atoms ofthe aryl-substituted aromatic ligands are replaced by halogen atoms, andmore preferred that the aromatic ligands be perhalogenated. Fluorine isthe most preferred halogen. The ligand descriptions of each theforegoing documents are incorporated by reference for information andU.S. patent practice purposes.

The R group, or ligand, may also be a covalently bonded metal/metalloidoxide or polymeric support. Lewis base-containing support substrateswill react with the Lewis acidic cocatalyst activators of the inventionto form support bonded Lewis acid compounds where one R group of R_(n)Al(ArHal)_(3-n) is a covalently bonded support substrate. The Lewis basehydroxyl groups of silica are exemplary of metal/metalloid oxides wherethis method of bonding to a support at one of the aluminum coordinationsites occurs.

Accordingly, the metal or metalloid oxide supports of the inventioninclude any metal/metalloid oxides, preferably those having surfacehydroxyl groups exhibiting a pK_(a) equal to or less than that observedfor amorphous silica, i.e., pK_(a) less than or equal to about 11. Informing the invention, covalently bound anionic activator, the Lewisacid, is believed to form initially a dative complex with a silanolgroup (which acts as a Lewis base) thus forming a formally dipolar(zwitterionic) Bronsted acid structure bound to the metal/metalloid ofthe metal oxide support. Thereafter the proton of the Bronsted acidappears to protonate an R-group of the Lewis acid, abstracting it, atwhich time the Lewis acid becomes covalently bonded to the oxygen atom.The replacement R group of the Lewis acid then becomes R'--O--, where R'is a suitable support substrate, e.g., silica or hydroxylgroup-containing polymeric support. Accordingly, any of theconventionally known inorganic oxides, silica, support materials thatretain hydroxyl groups after dehydration treatment methods will besuitable in accordance with the invention. Because of availability, bothof silica and silica containing metal oxide based supports, for example,silica-alumina, are preferred. Silica particles, gels and glass beadsare most typical.

These metal oxide compositions may additionally contain oxides of othermetals, such as those of Al, K, Mg, Na, Si, Ti and Zr and shouldpreferably be treated by thermal and/or chemical means to remove waterand free oxygen. Typically such treatment is in a vacuum in a heatedoven, in a heated fluidized bed or with dehydrating agents such asorgano silanes, siloxanes, alkyl aluminum compounds, etc. The level oftreatment should be such that as much retained moisture and oxygen as ispossible is removed, but that a chemically significant amount ofhydroxyl functionality is retained. Thus calcining at up to 800° C. ormore up to a point prior to decomposition of the support material, forseveral hours is permissible, and if higher loading of supported anionicactivator is desired, lower calcining temperatures for lesser times willbe suitable. Where the metal oxide is silica, loadings to achieve fromless than 0.1 mmol to 3.0 mmol activator/g SiO₂ are typically suitableand can be achieved, for example, by varying the temperature ofcalcining from 200 to 800+° C. See Zhuralev, et al, Langmuir 1987, Vol.3, 316 where correlation between calcining temperature and times andhydroxyl contents of silicas of varying surface areas is described.

The tailoring of hydroxyl groups available as attachment sites in thisinvention can also be accomplished by the pre-treatment, prior toaddition of the Lewis acid, with a less than stoichimetric amount of thechemical dehydrating agents. Preferably those used will be usedsparingly and will be those having a single ligand reactive with thesilanol groups (e.g., (CH₃)₄ SiCl), or otherwise hydrolyzable, so as tominimize interference with the reaction of the transition metal catalystcompounds with the bound activator. If calcining temperatures below 400°C. are employed, difunctional coupling agents (e.g., (CH₃)₃ SiCl₂) maybe employed to cap hydrogen bonded pairs of silanol groups which arepresent under the less severe calcining conditions. See for example,"Investigation of Quantitative SiOH Determination by the SilaneTreatment of Disperse Silica", Gorski, et al, Journ. of Colloid andInterface Science, Vol. 126, No. 2, Dec. 1988, for discussion of theeffect of silane coupling agents for silica polymeric fillers that willalso be effective for modification of silanol groups on the catalystsupports of this invention. Similarly, use of the Lewis acid in excessof the stoichimetric amount needed for reaction with the transitionmetal compounds will serve to neutralize excess silanol groups withoutsignificant detrimental effect for catalyst preparation or subsequentpolymerization.

Polymeric supports are preferably hydroxyl-functional-group-containingpolymeric substrates, but functional groups may be any of the primaryalkyl amines, secondary alkyl amines, and others, where the groups arestructurally incorporated in a polymeric chain and capable of aacid-base reaction with the Lewis acid such that a ligand filling onecoordination site of the aluminum is protonated and replaced by thepolymer incorporated functionality. See, for example, the functionalgroup containing polymers of U.S. Pat. No. 5,288,677.

Transition metal compounds suitable as olefin polymerization catalystsby coordination or insertion polymerization in accordance with theinvention will include the known transition metal compounds useful intraditional Ziegler-Natta coordination polymerization and as well themetallocene compounds similarly known to be useful in coordinationpolymerization, when such compounds are capable of catalytic activationby the cocatalyst activators described for the invention. These willtypically include Group 4 to 10 transition metal compounds wherein atleast one metal ligand can be abstracted by the cocatalyst activators,particularly those ligands including hydride, alkyl and silyl. Ligandscapable of abstraction and transition metal compounds comprising theminclude those metallocenes described in the background art, see forexample U.S. Pat. No. 5,198,401 and PCT Publication WO 92/00333.Syntheses of these compounds is well known from the publishedliterature. Additionally, where the metal ligands include halogen, amidoor alkoxy moieties (for example, biscyclopentadienyl zirconiumdichloride) which are not capable of abstraction with the activatingcocatalysts of the invention, they can be converted into suitableligands via known alkylation reactions with organometallic compoundssuch as lithium or aluminum hydrides or alkyls, alkylalumoxanes,Grignard reagents, etc. See also EP-Al-0 570 982 for the reaction oforganoaluminum compounds with dihalo-substituted metallocene compoundsprior to addition of activating anion compounds. All documents citedherein are incorporated by reference for purposes of U.S. patentpractice.

Additional description of metallocene compounds which comprise, or canbe alkylated to comprise, at least one ligand capable of abstraction toform a catalytically active transition metal cation appear in the patentliterature, for example, U.S. Pat. Nos. 4,871,705, 4,937,299 and5,324,800 and EP-A-0 129 368, EP-A-0 418 044, EP-A-0 591 756, WO92/00333 and WO 94/01471. Such metallocene compounds can be describedfor this invention as mono- or bis-cyclopentadienyl substituted Group4,5, or 6 transition metal compounds wherein the ancillary ligands maybe themselves substituted with one or more groups and may be bridged toeach other, or may be bridged through a heteroatom to the transitionmetal. The size and constituency of the ancillary ligands and bridgingelements are not critical to the preparation of the ionic catalystsystems of the invention but should be selected in the literaturedescribed manner to enhance the polymerization activity and polymercharacteristics being sought.

Generally, bulky ligand metallocene-type catalyst compounds include halfand full sandwich compounds having one or more bulky ligands bonded toat least one metal atom. Typical bulky ligand metallocene-type compoundsare generally described as containing one or more bulky ligand(s) andone or more leaving group(s) bonded to at least one metal atom. In onepreferred embodiment, at least one bulky ligands is η-bonded to themetal atom, most preferably η⁵ -bonded to the metal atom. The bulkyligands are generally represented by one or more open, acyclic, or fusedring(s) or ring system(s) or a combination thereof. These bulky ligands,preferably the ring(s) or ring system(s) are typically composed of atomsselected from Groups 13 to 16 atoms of the Periodic Table of Elements,preferably the atoms are selected from the group consisting of carbon,nitrogen, oxygen, silicon, sulfur, phosphorous, germanium, boron andaluminum or a combination thereof. Most preferably the ring(s) or ringsystem(s) are composed of carbon atoms such as but not limited to thosecyclopentadienyl ligands or cyclopentadienyl-type ligand structures orother similar functioning ligand structure such as a pentadiene, acyclooctatetraendiyl or an imide ligand. The metal atom is preferablyselected from Groups 3 through 15 and the lanthanide or actinide seriesof the Periodic Table of Elements. Preferably the metal is a transitionmetal from Groups 4 through 12, more preferably Groups 4, 5 and 6, andmost preferably the transition metal is from Group 4. All documents areincorporated by reference for purposes of U.S. patent practice.

Metallocene compounds suitable for the preparation of polyethylene orethylene-containing copolymers (where copolymer means comprising atleast two different monomers) are essentially any of those known in theart, see again EP-A-0 277 004, WO 92/00333 and U.S. Pat. Nos. 5,001,205,5,198,401, 5,324,800, 5,308,816, and 5,304,614 for specific listings.Selection of metallocene compounds for use to make isotactic orsyndiotactic polypropylene, and their syntheses, are well-known in theart, specific reference may be made to both patent literature andacademic, see for example Journal of Organmetallic Chemistry 369,359-370 (1989). Typically those catalysts are stereorigid asymmetric,chiral, achiral or bridged chiral or achiral metallocenes. See forexample, U.S. Pat. Nos. 4,892,851, 5,017,714, 5,296,434 and 5,278,264,PCT/US92/10066 and WO-A-93/19103, and EP-A2-0 577 581, EP-A1-0 578 838,and academic literature "The Influence of Aromatic Substituents on thePolymerization Behavior of Bridged Zirconocene Catalysts", Spaleck, W.,et al, Organometallics 1994, 13, 954-963, and "ansa-ZirconocenePolymerization Catalysts with Annelated Ring Ligands-Effects onCatalytic Activity and Polymer Chain Lengths", Brinzinger, H., et al,Organometallics 1994, 13, 964-970, and documents referred to therein.Though many of the documents discussed above are directed to catalystsystems with alumoxane activators, the analogous metallocene compoundswill be useful with the cocatalyst activators of this invention foractive coordination catalyst systems, when the halogen, amide or alkoxycontaining ligands of the metals (where occurring) are replaced withligands capable of abstraction, for example, via an alkylation reactionas described above, and another is a group into which the ethylene group--C═C-- may insert, for example, hydride, alkyl, or silyl. All documentsare incorporated by reference for purposes of U.S. patent practice.

Representative metallocene compounds have the formula:

    L.sup.A L.sup.B L.sup.C.sub.i MAB

where, L^(A) is a substituted cyclopentadienyl or heterocyclopentadienylancillary ligand π-bonded to M; L^(B) is a member of the class ofancillary ligands defined for L^(A), or is J, a heteroatom ancillaryligand σ-bonded to M; the L^(A) and L^(B) ligands may be covalentlybridged together through a Group 14 element linking group; L^(C) _(i) isan optional neutral, nonoxidizing ligand having a dative bond to M (iequals 0 to 3); M is a Group 4 transition·metal; and, A and B areindependently monoanionic labile ligands, each having a σ-bond to M,optionally bridged to each other or L^(A) or L^(B), which can be brokenfor abstraction purposes by a suitable activator and into which apolymerizable monomer or macromonomer can insert for coordinationpolymerization.

Non-limiting representative metallocene compounds includemono-cyclopentadienyl compounds such aspentamethylcyclopentadienyltitanium isopropoxide,pentamethylcyclopentadienyltribenzyl titanium,dimethylsilyltetramethyl-cyclopentadienyl-tert-butylamido titaniumdichloride, pentamethylcyclopentadienyl titanium trimethyl,dimethylsilyltetramethylcyclopentadienyl-tert-butylamido zirconiumdimethyl, dimethylsilyltetramethylcyclopentadienyl-dodecylamido hafniumdihydride, dimethylsilyltetramethylcyclopentadienyl-dodecylamido hafniumdimethyl, unbridged biscyclopentadienyl compounds such as bis(1,3-butyl,methylcyclopentadienyl) zirconium dimethyl,pentamethylcyclopentadienyl-cyclopentadienyl zirconium dimethyl,(tetramethylcyclopentadienyl)(n-propylcyclopetadienyl)zirconiumdimethyl; bridged bis-cyclopentadienyl compounds such asdimethylsilylbis(tetrahydroindenyl) zirconium dichloride andsilacyclobutyl(tetramethylcyclopentadienyl)(n-propyl-cyclopentadienyl)zirconium dimethyl; bridged bisindenyl compounds such asdimethylsilylbisindenyl zirconium dichloride, dimethylsilylbisindenylhafnium dimethyl, dimethylsilylbis(2-methylbenzindenyl) zirconiumdichloride, dimethylsilylbis(2-methylbenzindenyl) zirconium dimethyl;and fluorenyl ligand-containing compounds, e.g.,diphenylmethyl(fluorenyl)(cyclopentadienyl)zirconiumdimethyl; and theadditional mono- and bis-cyclopentadienyl compounds such as those listedand described in U.S. Pat. Nos. 5,017,714 and 5,324,800 and EP-A-0 591756. All documents are incorporated by reference for purposes of U.S.patent practice.

Representative traditional Ziegler-Natta transition metal compoundsinclude tetrabenzyl zirconium, tetra bis(trimethylsiylmethyl) zirconium,oxotris(trimethlsilylmethyl) vanadium, tetrabenzyl hafnium, tetrabenzyltitanium, bis(hexamethyl disilazido)dimethyl titanium, tris(trimethylsilyl methyl) niobium dichloride, tris(trimethylsilylmethyl) tantalumdichloride. The important features of such compositions for coordinationpolymerization are the ligand capable of abstraction and that ligandinto which the ethylene (olefinic) group can be inserted. These featuresenable the ligand abstraction from the transition metal compound and theconcomitant formation of the ionic catalyst composition of theinvention.

Additional organometallic transition metal compounds suitable as olefinpolymerization catalysts in accordance with the invention will be any ofthose Group 4 to 10 containing catalyst compounds that can be convertedby ligand abstraction into a catalytically active cation and stabilizedin that active electronic state by a noncoordinating or weaklycoordinating anion sufficiently labile to be displaced by anolefinically unsaturated monomer such as ethylene. Exemplary compoundsinclude those described in the patent literature. U.S. Pat. No.5,318,935 describes bridged and unbridged bisamido transition metalcatalyst compounds of Group 4 metals capable of insertion polymerizationof olefins. Publications WO 96/23010, WO 97/48735 and Gibson, et. al.,Chem. Comm., pp. 849-850 (1998), disclose diimine-based ligands forGroup 8 to 10 metal compounds shown to be suitable for ionic activationand olefin polymerization. Transition metal polymerization catalystsystems from Group 5 to 10 metals wherein the active transition metalcenter is in a high oxidation state and stabilized by low coordinationnumber polyanionic ancillary ligand systems are described in U.S. Pat.Nos. 5,502,124 and 5,504,049. Bridged bis(arylamido) Group 4 compoundsfor olefin polymerization are described by D. H. McConville, et al, inOrganometallics 1995, 14, 5478-5480. Synthesis methods and compoundcharacterization are presented. Further work appearing in D. H.McConville, et al, Macromolecules 1996, 29, 5241-5243, described thebridged bis(arylamido) Group 4 compounds are active catalysts forpolymerization of 1-hexene. Additional transition metal compoundssuitable in accordance with the invention include those described in WO96/40805. Each of these documents is incorporated by reference for thepurposes of U.S. patent practice.

Other transition metal catalyst compounds useful in the inventioninclude those having heteroatoms in the cyclopentadienyl ligands asdescribed in WO 96/33202, WO 96/34021, WO 97/17379 and WO 98/22486 andEP-A1-0 874 005 and U.S. Pat. Nos. 5,637,660, 5,539,124, 5,554,775,5,756,611, 5,233,049, 5,744,417, and 5,856,258 all of which are hereinincorporated by reference.

In another embodiment, the transition metal catalyst compounds are thosecomplexes known as transition metal catalysts based on bidentate ligandscontaining pyridine or quinoline moieties, such as those described inU.S. application Ser. No. 09/103,620 filed Jun. 23, 1998, which isherein incorporated by reference. Other metallocene catalyst includethose described in PCT publications WO 99/01481 and WO 98/42664, whichare fully incorporated herein by reference.

When using the catalysts of the invention, particularly when immobilizedon a support, the total catalyst system will generally additionallycomprise one or more scavenging compounds. The term "scavengingcompounds" as used in this application and its claims is meant toinclude those compounds effective for removing, preferably polar,impurities from the reaction environment. Impurities can beinadvertently introduced with any of the polymerization reactioncomponents, particularly with solvent, monomer and catalyst feed, andadversely affect catalyst activity and stability. It can result indecreasing or even elimination of catalytic activity, particularly whenionizing anion precursors activate the catalyst system. The polarimpurities, or catalyst poisons, include water, oxygen, metalimpurities, etc. Preferably steps are taken before provision of suchinto the reaction vessel, for example by chemical treatment or carefulseparation techniques after or during the synthesis or preparation ofthe various components, but some minor amounts of scavenging compoundmight still normally be used in the polymerization process itself.

Typically the scavenging compound will be an excess of the alkylatedLewis acids needed for initiation, as described above, or will beadditional known organometallic compounds such as the Group 13organometallic compounds of U.S. Pat. Nos. 5,153,157 and 5,241,025 andWO 91/09882, WO 94/03506, WO 93/14132, and WO 95/07941. Exemplarycompounds include triethyl aluminum, triethyl borane, triisobutylaluminum, methylalumoxane, isobutyl aluminumoxane, and tri-n-octylaluminum. Those scavenging compounds having bulky or C₆ -C₂₀ linearhydrocarbyl substituents covalently bound to the metal or metalloidcenter being preferred to minimize adverse interaction with the activecatalyst. Examples include triethylaluminum, but more preferably, bulkycompounds such as triisobutylaluminum, triisoprenylaluminum, andlong-chain linear alkyl-substituted aluminum compounds, such astri-n-hexylaluminum, tri-n-octylaluminum, or tri-n-dodecylaluminum. Whenalumoxane is used as an activator, any excess over the amount needed toactivate the catalysts present will act as scavenger compounds andadditional scavenging compounds may not be necessary. Alumoxanes alsomay be used in scavenging amounts with other means of activation, e.g.,methylalumoxane and triisobutyl-aluminoxane. The amount of scavengingagent to be used with Group 4 to 10 catalyst compounds of the inventionis minimized during polymerization reactions to that amount effective toenhance activity and avoided altogether if the feeds and polymerizationmedium can be sufficiently free of adventitious impurities.

The catalyst complexes of the invention are useful in polymerization ofunsaturated monomers conventionally known to be polymerizable undercoordination polymerization using metallocenes. Such conditions are wellknown and include solution polymerization, slurry polymerization,gas-phase polymerization, and high pressure polymerization. The catalystof the invention may be supported (preferably as described above) and assuch will be particularly useful in the known operating modes employingfixed-bed, moving-bed, fluid-bed, slurry or solution processes conductedin single, series or parallel reactors. Prepolymerization of supportedcatalyst of the invention may also be used for further control ofpolymer particle morphology in typical slurry or gas phase reactionprocesses in accordance with conventional teachings.

In alternative embodiments of olefin polymerization methods for thisinvention, the catalyst system is employed in liquid phase (solution,slurry, suspension, bulk phase or combinations thereof), in highpressure liquid or supercritical fluid phase, or in gas phase. Each ofthese processes may also be employed in singular, parallel or seriesreactors. The liquid processes comprise contacting olefin monomers withthe above described catalyst system in a suitable diluent or solvent andallowing said monomers to react for a sufficient time to produce theinvention copolymers. Hydrocarbyl solvents are suitable, both aliphaticand aromatic, hexane and toluene are preferred. Bulk and slurryprocesses are typically done by contacting the catalysts with a slurryof liquid monomer, the catalyst system being supported. Gas phaseprocesses typically use a supported catalyst and are conducted in anymanner known to be suitable for ethylene homopolymers or copolymersprepared by coordination polymerization. Illustrative examples may befound in U.S. Pat. Nos. 4,543,399, 4,588,790, 5,028,670, 5,382,638,5352,749, 5,436,304, 5,453,471 and 5,463,999, and PCT publication WO95/07942. Each document cited is incorporated by reference for purposesof U.S. patent practice.

Generally speaking the polymerization reaction temperature can vary fromabout 40° C. to about 250° C. Preferably the polymerization reactiontemperature will be from 60° C. to 220°, more preferably below 200° C.The pressure can vary from about 1 mm Hg to 2500 bar (2467 atm),preferably from 0.1 bar (0.1 atm) to 1600 bar (1579 atm), mostpreferably from 1.0 bar (0.98 atm) to 500 bar (490 atm).

Linear polyethylene, including high and ultra-high molecular weightpolyethylenes, including both homo- and co- polymers with otheralpha-olefin monomers, alpha-olefinic and/or non-conjugated diolefins,for example, C₃ -C₂₀ olefins, diolefins or cyclic olefins, are producedby adding ethylene, and optionally one or more of the other monomers, toa reaction vessel under low pressure (typically<50 bar (49 atm)), at atypical temperature of 40 to 250° C. with the invention catalyst thathas been slurried with a solvent, such as hexane or toluene. Heat ofpolymerization is typically removed by cooling. Gas phase polymerizationcan be conducted, for example, in a continuous fluid bed gas-phasereactor operated at 2000 to 3000 kPa and 60-160° C., using hydrogen as areaction modifier (for example, 100-200 ppm), C₄ -C₈ comonomerfeedstream (0.5 to 1.2 mol %), and C₂ feedstream (25 to 35 mol %). SeeU.S. Pat. Nos. 4,543,399, 4,588,790, 5,028,670 and 5,405,922 and5,462,999, which are incorporated by reference for purposes of U.S.patent practice.

Ethylene-α-olefin (including ethylene-cyclic olefin andethylene-α-olefin-diolefin) elastomers of high molecular weight and lowcrystallinity can be prepared utilizing the catalysts of the inventionunder traditional solution polymerization processes or by introducingethylene gas into a slurry utilizing the α-olefin or cyclic olefin ormixture thereof with other monomers, polymerizable and not, as apolymerization diluent in which the invention catalyst is suspended.Typical ethylene pressures will be between 10 and 1000 psig (69 to 6895kPa) and the polymerization diluent temperature will typically bebetween 40 and 160° C. The process can be carried out in a stirred tankreactor, or more than one operated in series or parallel. See thegeneral disclosure of U.S. Pat. No. 5,001,205 for general processconditions. See also PCT publication WO 96/33227 and WO 97/22639. Alldocuments are incorporated by reference for description ofpolymerization processes, metallocene selection and useful scavengingcompounds.

Other olefinically unsaturated monomers besides those specificallydescribed above may be polymerized using the catalysts according to theinvention, for example, styrene, alkyl-substituted styrene, isobutylene,ethylidene norbomene, norbomadiene, dicyclopentadiene, and otherolefinically-unsaturated monomers, including other cyclic olefins, suchas cyclopentene, norbornene, and alkyl-substituted norbomenes.Additionally, alpha-olefinic macromonomers of up to 1000 mer units, ormore, may also be incorporated by copolymerization.

Polymer Products

The polymers produced by the process of the invention can be used in awide variety of products and end-use applications. The polymers producedby the process of the invention include linear low density polyethylene,elastomers, plastomers, high density polyethylenes, low densitypolyethylenes, polypropylene and polypropylene copolymers.

The polymers, typically ethylene based polymers, have a density in therange of from 0.86 g/cc to 0.97 g/cc, preferably in the range of from0.88 g/cc to 0.965 g/cc, more preferably in the range of from 0.900 g/ccto 0.96 g/cc, even more preferably in the range of from 0.905 g/cc to0.95 g/cc, yet even more preferably in the range from 0.910 g/cc to0.940 g/cc, and most preferably greater than 0.915 g/cc, preferablygreater than 0.920 g/cc, and most preferably greater than 0.925 g/cc.Density is measured in accordance with ASTM-D-1238.

The polymers produced by the process of the invention typically have amolecular weight distribution, a weight average molecular weight tonumber average molecular weight (M_(w) /M_(n)) of greater than 1.5 toabout 4, particularly greater than 2 to about 3.5, more preferablygreater than about 2 to less than about 3, and most preferably fromabout 2 to 3.

The melt strength of the polymers produced using the catalyst of theinvention are in the range of from 6.5 cN to about 11 cN, preferablyfrom 7 cN to 11 cN, and more preferably in the range of from 7 cN to 10cN, and most preferably in the range of from 7 to 10 at a I₂ of about 1g/10 min. For purposes of this patent application and appended claimsmelt strength is measured with an Instron capillary rheometer inconjunction with the Goettfert Rheotens melt strength apparatus. Apolymer melt strand extruded from the capillary die is gripped betweentwo counter-rotating wheels on the apparatus. The take-up speed isincreased at a constant acceleration of 24 mm/sec², which is controlledby the Acceleration Programmer (Model 45917, at a setting of 12). Themaximum pulling force (in the unit of cN) achieved before the strandbreaks or starts to show draw-resonance is determined as the meltstrength. The temperature of the rheometer is set at 190° C. Thecapillary die has a length of one inch (2.54 cm) and a diameter of 0.06"(0.1 5cm). The polymer melt is extruded from the die at a speed of 3inch/min (7.62 cm/min). The distance between the die exit and the wheelcontact point should be 3.94 inches (100 mm).

In preferred embodiment, the Melt Strength (MS) (measured in cN) of thepolymers of the invention satisfy the following equation:

    MS≧6.5-5.2*log(MI)

wherein MI is the Melt Index or I₂ as determined using ASTM-D-1238-E. Itis even more preferable that the MI in the formula above be in the rangeof from 0.4 dg/min to 5 dg/min., yet even more preferably from 0.5dg/min to 4 dg/min, and most preferably from about 0.5 dg/min to 3dg/min, especially for use in producing a film grade product.

Also, the polymers of the invention typically have a narrow compositiondistribution as measured by Composition Distribution Breadth Index(CDBI). Further details of determining the CDBI of a copolymer are knownto those skilled in the art. See, for example, PCT Patent Application WO93/03093, published Feb. 18, 1993, which is fully incorporated herein byreference. The polymers of the invention in one embodiment have CDBI'sgenerally in the range of greater than 50% to 100%, preferably 99%,preferably in the range of 55% to 85%, and more preferably 60% to 80%,even more preferably greater than 60%, still even more preferablygreater than 65%.

The polymers of the present invention in one embodiment have a meltindex (MI) or (I₂) as measured by ASTM-D-1238-E in the range from 0.01dg/min to 100 dg/min, more preferably from about 0.01 dg/min to about 10dg/min, even more preferably from about 0.1 dg/min to about 5 dg/min,and most preferably from about 0.1 dg/min to about 3 dg/min.

The polymers of the invention in an embodiment have a melt index ratio(I₂₁ /I₂) (₂₁ is measured by ASTM-D-1238-F) of from 10 to less than 25,more preferably from about 15 to less than 25 and most preferably fromabout 15 about 20.

In yet another embodiment, propylene based polymers are produced in theprocess of the invention. These polymers include atactic polypropylene,isotactic polypropylene, hemiisotactic and syndiotactic polypropylene.Other propylene polymers include propylene block or impact copolymers.Propylene polymers of these types are well known in the art see forexample U.S. Pat. Nos. 4,794,096, 3,248,455, 4,376,851, 5,036,034 and5,459,117, all of which are herein incorporated by reference.

The polymers of the invention may be blended and/or coextruded with anyother polymer. Non-limiting examples of other polymers include linearlow density polyethylenes produced via conventional Ziegler-Natta and/orbulky ligand metallocene-type catalysis, elastomers, plastomers, highpressure low density polyethylene, high density polyethylenes,polypropylenes and the like.

Polymers produced by the process of the invention and blends thereof areuseful in such forming operations as film, sheet, and fiber extrusionand co-extrusion as well as blow molding, injection molding and rotarymolding. Films include blown or cast films formed by coextrusion or bylamination useful as shrink film, cling film, stretch film, sealingfilms, oriented films, snack packaging, heavy duty bags, grocery sacks,baked and frozen food packaging, medical packaging, industrial liners,membranes, etc. in food-contact and nonfood contact applications. Fibersinclude melt spinning, solution spinning and melt blown fiber operationsfor use in woven or non-woven form to make filters, diaper fabrics,medical garments, geotextiles, etc. Extruded articles include medicaltubing, wire and cable coatings, pipe, geomembranes, and pond liners.Molded articles include single and multilayered constructions in theform of bottles, tanks, large hollow articles, rigid food containers andtoys, etc.

EXAMPLES

The following examples are presented to illustrate the foregoingdiscussion. All parts, proportions and percentages are by weight unlessotherwise indicated. All examples were carried out in dry, oxygen-freeenvironments and solvents. Although the examples may be directed tocertain embodiments of the present invention, they are not to be viewedas limiting the invention in any specific respect. In these examplescertain abbreviations are used to facilitate the description. Theseinclude standard chemical abbreviations for the elements and certaincommonly accepted abbreviations, such as : Me=methyl, THF, orthf,=tetrahydrofuran, and Cp*, permethylated cyclopentadienyl metalligand.

All molecular weights are weight average molecular weight unlessotherwise noted. Molecular weights (weight average molecular weight(M_(w)) and number average molecular weight (M_(n)) and (M_(z)) weremeasured by Gel Permeation Chromatography (GPC) as described below.

Examples 1 to 4 M_(w) /M_(n) determinations were measured using a Waters150 Gel Permeation Chromatograph equipped with a differential refractiveindex detector and calibrated using a broad calibration based onSRM-1475 (a linear Polyethylene standard obtained from NBS). Sampleswere run in 1,2,4-trichlorobenzene at 145° C. with a concentration of1.5 mg/ml. The injection volume was 300 μl. The column set was threeShodex GPC AT-806 MS columns in series. This general technique isdiscussed in "Liquid Chromatography of Polymers and Related MaterialsIII", J. Cazes Ed., Marcel Decker, 1981, Page 207.

Examples 21 and 22 M_(w) /M_(n) determinations were measured using aWaters 150 Gel Permeation Chromatograph equipped with a differentialrefractive index detector and calibrated using polystyrene standards.Samples were run in 1,2,4-trichlorobenzene at 135° C. with aconcentration of 1.0 to 1.5 mg/ml. The injection volume was 300 μl. Thecolumn set was three Polymer Laboratories PLGEL Mixed-B columns (withflow rate of 0.5 ml/min.). This general technique is discussed in"Liquid Chromatography of Polymers and Related Materials III", J. CazesEd., Marcel Decker, 1981, Page 207. For purposes of the appended claimsthe GPC method described for Examples 21 and 22 for determining M_(w),M_(n) or M_(z) is to be used.

Tris-pentafluorophenylborane was purchased from Boulder ScientificCompany and used as received. Anhydrous toluene and pentane waspurchased from Aldrich. X-Ray Diffraction studies were performed byCrystalytics Company.

I. Unsupported Catalysts Example A (Synthesis)

1. [(CH₃)₂ CHCH₂)Al(C₆ F₅)₂ ]₂ -isobutyl aluminum di(pentafluorophenyl)B(C₆ F₅)₃ (20.5 grams) was dissolved in toluene previously dried oversodium/potassium alloy. Triisobutylaluminum (15.8 grams) was addeddropwise to the B(C₆ F₅)₃ toluene solution. The solvent was removedunder vacuum, pentane was added, and the solution was cooled to -30° C.The resulting white crystalline solid was dried under vacuum. An X-raydiffraction study of a crystal of this complex revealed a dimer complexin the solid state with the following formula: [Al(μ,η² -C₆ F₅)(C₆F₅)(i-C₄ H₉)]₂. ¹⁹ F NMR (C₆ D₆ ; ref. to CF₃ C₆ H₅ δ=-62.5) δ-121.2,-151.2, -160.7. ¹ H NMR (C₆ D₆) δ0.53 d, 0.98 d, 1.88 m.

Example B (Synthesis)

2. [(CH₃)Al(C₆ F₅)₂ ]_(n) was synthesized analogous to the proceduredescribed in the above synthesis of [(CH₃)₂ CHCH₂)Al(C₆ F₅)₂ ]₂.

Polymerization Process

This following is a general description of the polymerization processused with catalysts of the invention. Polymerizations were conducted ina stainless steel, 1-liter Zipperclave autoclave reactor. The reactorwas equipped with water jacket for heating and cooling. Injections weretypically done through a septum inlet or were injected via a highpressure nitrogen injection. Before the polymerizations, the reactor waspurged with nitrogen for several hours at 100° C. Upon injection of thecatalyst, ethylene or ethylene and hexene-1 was fed continuously ondemand keeping the reactor pressure constant while maintaining thereaction temperature at 60° C. After a period of time the reaction wasstopped by cooling and venting the pressure and exposing the contents ofthe reactor to air. The liquid components were evaporated and theethylene homopolymer or ethylene/hexene-1 copolymer was dried in avacuum oven. Weight average molecular weight (M_(w)), number averagemolecular weight (M_(n)) and their ratio M_(w) /M_(n) were obtained bygel permeation chromatography (GPC) as described above. Hexene weightpercent (wt %) incorporation was obtained from FTIR calibration data.

Example 1

Me₂ Si(H₄ -indenyl)₂ Zr(CH₃)₂) (₂₀ mg) and [Al(μ,η² -C₆ F₅)(C₆ F₅)(i-C₄H₉)]₂ (40 mg) were combined in 10 mls of toluene. The resulting solutionis yellow. Using the polymerization process described above, 2 mls ofthe catalyst precursor solution was injected into a 1 L stainless steelreactor preheated to 60° C. containing 45 mls of hexene-1, 75 psi (517kPa) of ethylene, and 500 mls of hexane. After 40 minutes thepolymerization reaction was stopped and 26.2 grams of polymer wasisolated. The polymer produced had a M_(w) =79900, M_(n) =18600, M_(w)/M_(n) =4.30 and Hexene wt %=20.

Example 2

Me₂ Si(H₄ -indenyl)₂ Zr(CH₃)₂) (20 mg) and [Al(C₆ F₅)₂ (CH₃)]_(n) (40mg) were combined in 10 mls of toluene. The resulting solution isyellow. Using the polymerization process described above,1.5 mls of thecatalyst precursor solution was injected into a 1 L stainless steelreactor preheated to 60° C. containing 45 mls of hexene-1, 75 psi (517kPa) of ethylene, and 500 mls of hexane. After 30 minutes thepolymerization reaction was stopped and 12.2 grams of polymer wasisolated. The polymer produced had a M_(w) =109000, M_(n) =16300, M_(w)/M_(n) =6.69 and Hexene wt %=19.

Example 3

(Cp)₂ Zr(CH₃)₂) (20 mg) and [Al(μ,η² -C₆ F₅)(C₆ F₅)(i-C₄ H₉)]₂ (56) werecombined in 10 mls of toluene. The resulting solution is yellow. Usingthe polymerization process described above, 4 mls of the catalystprecursor solution was injected into a 1 L stainless steel reactorpreheated to 60° C. containing 75 psi (517 kPa) of ethylene, and 500 mlsof hexane. After 1 hour the polymerization reaction was stopped and 25.3grams of polymer was isolated. The polymer produced had a M_(w) =344000,M_(n) =153000 and M_(w) /M_(n) =2.25.

Example 4

(Cp)₂ Zr(CH₃)₂) (20 mg) and [Al(C₆ F₅)₂ (CH₃)]_(n) (42 mg) were combinedin 10 mls of toluene. The resulting solution is yellow. Using thepolymerization process described above, 4 mls of the catalyst precursorsolution was injected into a 1 L stainless steel reactor preheated to60° C. containing 75 psi (517 kPa) of ethylene, and 500 mls of hexane.After 1 hour the polymerization reaction was stopped and 22.1 grams ofpolymer was isolated. The polymer produced had a M_(w) =337000, M_(n)=154000 and a M_(w) /M_(n) =2.19.

II. Supported Catalysts

Tris-pentafluorophenylborane was purchased from Boulder ScientificCompany, and used as received. Al(C₆ F₅)₃ was prepared according themethod of Biagini, P. et al., as described in EP 0 694 548, hereinincorporated by reference. Anhydrous toluene and pentane, and methyllithium was purchased from Aldrich. The toluene was further dried over asodium/potassium alloy. The silica used herein was obtained from W. R.Grace, Davison Division, Baltimore, Md. Triethylaluminum was purchasedfrom Akzo Nobel, LaPorte, Texas. (1,3-BuMeCp)₂ ZrCl₂ was purchased fromBoulder Scientific Company, (1,3-BuMeCP)₂ ZrMe₂ was obtained by thereaction of two equivalents of methyl lithium in diethyl ether. Me₂Si(H₄ -indenyl)₂ Zr(CH₃)2) was obtained from Witco Corporation, Memphis,Tenn. In the following examples, .tbd.Si-- is a 4-coordinate siliconatom of silica additionally bonded to the activating cocatalyst moietyidentified.

Example 5 (Support Preparation)

.tbd.Si--O--Al(C₆ F₅)₂ A (600C)

Al(C₆ F₅)₃ (toluene) (10.8 grams) was added to a dry toluene slurry ofsilica (50.0 grams)(Davison 948 calcined at 600° C., available from W.R. Grace, Davison Division, Baltimore, Md.) at room temperature. Themixture was stirred, filtered, and dried under vacuum. An analogousreaction was performed in deuterated benzene. Elemental analysis showedaluminum 0.87 wt. % and carbon 4.94 wt. %. Note: Integration of theproton resonances in the ¹ H NMR spectrum of the removed solventrevealed the formation of approximately one equivalent ofpentafluorobenzene per equivalent of toluene (Eq. 1, below). (C6D6:δ2.1(s, 2.99H), 5.8 (m, 0.755H), 7.0 (m, 4.75H).

Tris-pentafluorophenylaluminum was reacted with silica (Davison 948,600° C. and 800° C., both of which are available from W. R. Grace,Davison Division, Baltimore, Md.) to liberate pentafluorobenzene, Eq. 1.For example, Davison 948 dehydrated at 600° C. silica with approximately0.6 mmoles --OH per gram of silica was reacted with one equivalent ofAl(C₆ F₅)₃ (toluene) per equivalent of --OH in deuterated benzene. Afterapproximately 24 hours the slurry was filtered and an ¹ HNMR spectrum ofthe solvent revealed an approximate one to one ratio of toluene topentafluorobenzene indicating the reaction shown in Eq. 1 had takenplace. ##STR1##

Example 6 (Support Preparation)

.tbd.Si--O--Al(C₆ F₅)₂ /.tbd.Si--O--AlEt₂ A (600C)

Triethylaluminum (0.52 grams) was added to a dry toluene slurry of (10.5grams) silica .tbd.Si--O--Al(C₆ F₅)₂ A (600C) (as prepared in Example 5)at room temperature. The mixture was stirred, filtered, and dried undervacuum. Elemental analysis showed an aluminum 2.26 wt. %, carbon 3.57wt. % and hydrogen 3.57 wt. %. Note: Triethylaluminum was added tofurther remove residual Si--OH groups on the silica.

Example 7 (Support Preparation)

.tbd.Si--O--Al(C₆ F₅)₂ (800C)

Al(C₆ F₅)₃ (toluene) (3.5 grams) was added to a dry toluene slurry ofsilica (20.0 grams)(Davison 948 calcined at 800° C., available from W.R. Grace, Davison Division, Baltimore, Md.) at room temperature. Themixture was stirred, filtered, and dried under vacuum.

Example 8 (Support Preparation)

.tbd.Si--O--Al(C₆ F₅)₂ /.tbd.Si--O--AlEt₂ (800C)

Triethylaluminum (0.6 grams) was added to a dry toluene slurry of silica.tbd.Si--O--Al(C₆ F₅)₂ (800C) (as prepared in Example 7) (16 grams) atroom temperature. The mixture was stirred, filtered, and dried undervacuum. Elemental analysis showed aluminum 1.55 wt. % and carbon 5.88wt. %.

Example 9 (Support Preparation)

.tbd.Si--O--Al(C₆ F₅)₂ B (600C)

Al(C₆ F₅)₃ (toluene) (3.0 grams) was added to a dry toluene slurry ofsilica .tbd.Si--O--Al(C₆ F₅)₂ A (600C) (16 grams) at room temperature.The slurry was stirred overnight, filtered, washed with dry toluene, anddried under vacuum. Elemental analysis showed aluminum 1.76 wt. % andcarbon 5.61 wt. %.

Example 10 Catalyst A Preparation

2.00 grams of silica (.tbd.Si--O--Al(C₆ F₅)₂ A (600C)) as prepared inExample 5 was slurried in 20 ml of dry toluene at room temperature.(1,3-BuMeCp)₂ ZrMe₂ (0.27 grams) in 3 mls of toluene was added to theslurried support. The support appeared yellow in the slurry which uponfiltering and washing with dry toluene resulted in a yellow powder. Thetoluene washings were almost colorless, indicative of retention of thecatalyst on the support.

Slurry-Phase Ethylene-Hexene Polymerization Using Catalyst A

Polymerizations were conducted in a stainless steel, 1-liter Zipperclaveautoclave reactor. The reactor was equipped with water jacket forheating and cooling. Injections were performed via a high pressurenitrogen injection. (400 mls isobutane, 30 mls of hexene, and 15 μlstriethylaluminum or 100 μls triisobutylaluminum. Before polymerizationsthe reactor was purged with nitrogen for several hours at 100° C. Uponinjection of catalyst ethylene was fed continuously on demand keepingthe reactor pressure constant (130 psig (896 kPa) ethylene) whilemaintaining the reaction temperature at 85° C. After a period of timethe reaction was stopped by cooling, venting the pressure and exposingthe contents of the reactor to air. The liquid components wereevaporated and the ethylene/hexene-1 copolymer was dried under a N₂purge. Weight average molecular weight (M_(w)), number average molecularweight (M_(n)) and their ratio M_(w) /M_(n) were obtained by GPC asdescribed above. Hexene-1 wt % incorporation was obtained from ¹ HNMRdata.

The above procedure was performed using 25 mgs of Catalyst A. After 40minutes the reaction was stopped. No reactor fouling was observed and16.8 grams of polymer resin (1120 g pol./g cat. h) was obtained. Note:After several days the activity of the catalyst had degraded.

Example 11 Catalyst B Preparation

.tbd.2.00 grams of silica .tbd.Si--O--Al(C₆ F₅)₂ /.tbd.Si--O--AlEt₂ A(600C) (as prepared in Example 5) was slurried in 20 ml of dry tolueneat room temperature. (1,3-BuMeCp)₂ ZrMe₂ (0.22 grams) in 3 mls oftoluene was added to the slurried support. The support appeared brown inthe slurry which upon filtering and washing with dry toluene resulted ina tan powder. The yellow toluene washings were removed and 0.12 grams ofunreacted metallocene was obtained. Elemental analysis showed zirconium1.16 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization using Catalyst B

The polymerization was run according to the procedure outlined inExample 10 using catalyst B. No reactor fouling was observed and thepolymer resin yield was 39.5 grams (2370 g pol./g cat. h). Duplicateruns over several days gave yield activities of 1280 g pol./g cat. h;1430 g pol./g cat. h; 1980 g pol./g cat. h (cat. stored at -30° C. forseveral days).

Example 12 Catalyst C Preparation

Catalyst C was prepared according to the method of Example 10 using 0.14grams of (1,3-BuMeCp)₂ ZrMe₂ except that the silica, .tbd.Si--O--Al(C₆F₅)₂ (800C) (as prepared in Example 7) was used instead of the silica(.tbd.Si--O--Al(C₆ F₅)₂ A (600C)). Elemental analysis showed zirconium1.39 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization using Catalyst C

The polymerization was run according to the procedure outlined inExample 10 except catalyst C was used. No reactor fouling was observedand the polymer resin yield was 20.9 grams (1390 g pol./g cat. h).

Example 13 Catalyst D Preparation

Catalyst D was prepared according to the method of Example 10 using0.042 grams of (1,3-BuMeCp)₂ ZrMe2 except that the silica,.tbd.Si--O--Al(C₆ F₅)₂ (800C) was used instead of the silica(.tbd.Si--O--Al(C₆ F₅)₂ A (600C)). Elemental analysis showed zirconium0.43 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization Using Catalyst D

The polymerization was run according to the procedure outlined inExample 10 except catalyst D was used. No reactor fouling was observedand the polymer resin yields for three runs were 9.03 grains (602 gpol./g cat. h), 9.21grams (614 g pol./g cat. h), 8.96 grams (597 gpol./g cat. h).

Example 14 Catalyst E Preparation

Catalyst E was prepared according to the method of Example 10 using 0.14grams of (1,3-BuMeCp)₂ ZrMe₂ except that the silica, .tbd.Si--O--Al(C₆F₅)₂ /.tbd.Si--O--AlEt₂ (800C) (as prepared in Example 7) was usedinstead of the silica (.tbd.Si--O--Al(C₆ F₅)₂ A (600C)). Elementalanalysis showed zirconium 1.10 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization Using Catalyst E

The polymerization was run according to the procedure outlined inExample 10 except Catalyst E was used. No reactor fouling was observedand the polymer resin yield was 10.36 grains (691 g pol./g cat. h).

Example 15 Catalyst F Preparation

Catalyst F was prepared according to the method of Example 10 using0.0453 grams of Me₂ Si(H₄ -indenyl)₂ Zr(CH₃)₂) except that the silica,.tbd.Si--O--Al(C₆ F₅)₂ /.tbd.Si--O--AlEt₂ A (600C) (as prepared inExample 6) was used instead of the silica (.tbd.Si--O--Al(C₆ F₅)₂ A(600C)). Elemental analysis showed zirconium 0.38 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization using Catalvst F

The polymerization was run according to the procedure outlined inExample 10 except Catalyst F was used and 20 mls of hexene was usedinstead of 30 mls hexene. No reactor fouling was observed and thepolymer resin yields were 4.11 grams (274 g pol./g cat. h), 7.83 grams(522 g pol./g cat. h).

Example 16 Catalyst G Preparation

Catalyst G was prepared according to the method of Example 10 using0.045 grams of Me₂ Si(H₄ -indenyl)₂ Zr(CH₃)₂) except that the silica,.tbd.Si--O--Al(C₆ F₅)₂ (800C) was use instead of the silica(.tbd.Si--O--Al(C₆ F₅)₂ A (600C)). Elemental analysis showed zirconium0.42 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization Using Catalyst G

The polymerization was run according to the procedure outlined inExample 10 Catalyst G was used and 20 mls of hexene-1 was used insteadof 30 mls hexene-1. No reactor fouling was observed and the polymerresin yields were 8.27 grams (551 g pol./g cat. h), 6.27 grams (418 gpol./g cat. h), 6.51 grams (434 g pol./g cat. h).

Example 17 Catalyst H Preparation

Catalyst H was prepared according to the method of Example 10 using 0.10grams of (1,3-BuMeCp)₂ ZrMe₂ except that the silica, (.tbd.Si--O--Al(C₆F₅)₂ B (600C)) was used instead of the silica (.tbd.Si--O--Al(C₆ F₅)₂ A(600C)). Elemental analysis; zirconium 1.07 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization Using Catalyst H

The polymerization was run according to the procedure outlined inExample 10 except Catalyst H was used. No reactor fouling was observedand the polymer resin yield was 53.95 grams (3597 g pol./g cat. h).Note: Enhanced polymerization activity was noted upon allowing thetrisperfluorophenylaluminum complex longer contact time with(.tbd.Si--OH) (overnight versus several hours). Furthermore, catalystactivity did not degrade with catalysts prepared with (.tbd.Si--O--Al(C₆F₅)₂ B (600C)) support/activator. However, we found that overnightreactions or longer with the silica supports should not be stirred witha stir bar. The stir bar crushes the silica particles overnight intovery fine dust.

Example 18 Catalyst I Preparation

Catalyst I was prepared according to the method of Example 10 using 0.05grams of Me₂ Si(H₄ -indenyl)₂ Zr(CH₃)₂) except that the silica,(.tbd.Si--O--Al(C₆ F₅)₂ B (600C)) was used instead of the silica(.tbd.Si--O--Al(C₆ F₅)₂ A (600C)). Elemental analysis showed zirconium0.68 wt. %.

Slurry-Phase Ethylene-Hexene Polymerization Using Catalyst I

The polymerization was run according to the procedure outlined inExample 10 except Catalyst I was used and 20 mls of hexene was usedinstead of 30 mls hexene. No reactor fouling was observed and thepolymer resin yield was 6.67 grams (445 g pol./g cat. h).

Example 19 Catalyst J Preparation

Catalyst J was prepared according to the method of Example 10 using0.043 grams of (1,3-BuMeCp)₂ ZrMe₂. The silica, (.tbd.Si--O--Al(C₆ F₅)₂(600C)) was prepared assuming 0.8 mmoles of hydroxyl content per gram ofsilica. Residual Al(C₆ F₅)₃ was filtered off after allowing the slurryto sit overnight without stirring.

Slurry-Phase Ethylene-Hexene Polymerization Using Catalyst J

The polymerization was run according to the procedure outlined inExample 10 except Catalyst J was used and 100 mls of triisobutylaluminumwere injected into the reactor in place of 15 mls of triethylaluminum.No reactor fouling was observed and the polymer resin yield was 76.2grams (5080 g pol./g cat. h).

Example 20 (Support Preparation)

100 grams of .tbd.Si--O--H (Davison 948 calcined @ 600° C., availablefrom W. R. Grace, Davison Division, Baltimore, Md.) was combined with atoluene solution of MeAl(C₆ F₅)₂ prepared from 27 grams of Al(C₆ F₅)₃(toluene) and 1.56 grams of trimethylaluminum. Vigorous methaneevolution was observed. The resulting slurry was stirred for severalhours after which stirring was stopped and the slurry was left overnightunder a nitrogen atmosphere. The silica was filtered and dried under avacuum.

Example 21 (Catalyst Preparation) Catalyst K

30 grams of this .tbd.Si--O--Al(C₆ F₅)₂ (as prepared in Example 20) intoluene was combined with 1.18 grams of (1,3-BuMeCp)₂ ZrMe₂. The slurrywas stirred 1.5 hours during which a dark orange/brown color develops.The slurry was filtered and the supported catalyst was dried undervacuum (salmon colored support).

Example 22 (Catalyst Preparation) Catalyst L

30 grams of this .tbd.Si--O--Al(C₆ F₅)₂ (as prepared in Example 20) intoluene was combined with 2.25 grams of (PropylCp)₂ HfMe2. The slurry asstirred 1.5 hours during which a yellow color develops. The slurry wasfiltered and the supported catalyst was dried under vacuum (yellowcolored support).

Polymerization Process

All the catalysts prepared in Examples 21 and 22 were screened in afluidized bed reactor equipped with devices for temperature control,catalyst feeding or injection equipment, GC analyzer for monitoring andcontrolling monomer and gas feeds and equipment for polymer sampling andcollecting. The reactor consists of a 6 inch (15.24 cm) diameter bedsection increasing to 10 inches (25.4 cm) at the reactor top. Gas comesin through a perforated distributor plate allowing fluidization of thebed contents and polymer sample is discharged at the reactor top.

                  TABLE 1                                                         ______________________________________                                        Example Number     22         21                                              ______________________________________                                        Temperature (° F.) (° C.)                                                          175 (79.4) 175 (79.4)                                        Pressure (psi) (kPa) 300 (2067) 300 (2067)                                    Ethylene (mole %) 34.9 35.1                                                   Hydrogen (mole ppm) 178 97                                                    Hydrogen/Ethylene Concentration ratio 5.1 2.8                                 Hexene (mole %) 0.34 0.59                                                     Hexene/Ethylene Concentration 0.0753 0.079                                    Bed Weight (g) 1911 1912                                                      Residence Time (hrs) 4.4 4.8                                                  Productivity.sup.1 (g/g) 1091 1912                                            Gas Velocity (ft/sec) (cm/sec) 1.51 (46) 1.61 (49)                            Production Rate (g/hr) 435 398                                                Bulk Density (g/cc) 0.4153 0.3970                                           ______________________________________                                         .sup.1 Productivity is number of grams of product per gram of catalyst.  

                  TABLE 2                                                         ______________________________________                                        Example Number       22        21                                             ______________________________________                                        Density (g/cc)       0.918     0.918                                            Melt Index (g/10 min) (I.sub.2) 0.88 1.06                                     Melt Index Ratio (MIR) (I.sub.21 /I.sub.2) 18.8 17.3                          Melt Strength (cN) 7.8 9.5                                                    M.sub.n  44,500  45,900                                                       M.sub.w 124,000 110,700                                                       M.sub.z 254,200 199,300                                                       M.sub.w /M.sub.n 2.79 2.41                                                    M.sub.z /M.sub.w 2.05 1.80                                                    CDBI (%) 68.1 52.2                                                            Weight % Hexene 7.9 7.9                                                       Mole % Hexene 2.8 2.8                                                       ______________________________________                                    

While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to variations notnecessarily illustrated herein. For example, it is contemplated that twoor more catalysts of the invention can be used or a catalyst system ofthe invention with any other metallocene/alumoxane supported orunsupported catalyst system. In addition two different Lewis acidaluminum compounds of the invention may be used in conjunction with anorganometallic catalyst compound or transition metal catalyst compound.Alternatively, a Lewis acid aluminum compound of the invention and aLewis acid boron compound may be used in conjunction with anorganometallic catalyst compound. For this reason, then, referenceshould be made solely to the appended claims for purpose of determiningthe true scope of the present invention.

What is claimed is:
 1. A process for the preparation of polyolefins from one or more olefinic monomers comprising combining said olefins under olefin polymerization conditions with an organometallic catalyst compound that is activated for olefin polymerization by reaction with a Lewis acid aluminum compound of the formula:

    R.sub.n Al(ArHal).sub.3-n,

wherein "ArHal" is a halogenated aryl group, n=1 or 2, and R is a monoanionic group other than a halogenated aryl group.
 2. The process of claim 1 wherein said monoanionic group is one or two groups selected from a group consisting of hydride, C₁ -C₃₀ hydrocarbyl and substituted hydrocarbyl, alkoxide and aryloxide, siloxide, halocarbyl and substituted halocarbyl, bridged and unbridged dialkylamido, and hydrocarbyl and halocarbyl substituted organometalloid.
 3. The process of claim 1 wherein said organometallic catalyst compound is a Group 3 to 10 transition metal compound capable of activation for olefin polymerization by ligand abstraction.
 4. The process of claim 1 wherein said organometallic catalyst compound is a Group 4 metallocene compound having the formula:

    L.sup.A L.sup.B L.sup.C.sub.i MAB

where, L^(A) is a substituted or unsubstituted cyclopentadienyl or heterocyclopentadienyl ancillary ligand η-bonded to M; L^(B) is a member of the class of ancillary ligands defined for L^(A), or is J, a heteroatom ancillary ligand σ-bonded to M; the L^(A) and L^(B) ligands may be covalently bridged together through a Group 14 element linking group; L^(C) _(i) is an optional neutral, non-oxidizing ligand having a dative bond to M (i equals 0 to 3); M is a Group 4 transition metal; and, A and B are independently monoanionic labile ligands, each having a σ-bond to M, optionally bridged to each other or L^(A) or L^(B), which can be broken for abstraction purposes by a suitable activator and into which a polymerizable monomer or macromonomer can insert for coordination polymerization.
 5. The process of claim 1 wherein said olefin polymerization conditions comprise a solution, supercritical pressure, bulk, slurry or gas phase process conducted at reaction temperatures between -20° C. to 200° C. and pressures between 0 to 2000 bar (1960 atm).
 6. The process of claim 4 wherein said process is bulk, slurry or gas phase, n=1 and R is a covalent connecting group linking the aluminum atom of said Lewis acid to a metal/metalloid support or polymeric support.
 7. The process of claim 6 wherein said support is silica.
 8. The process of claim 6 wherein said support is polymeric.
 9. The process of claim 4 wherein M is titanium and L^(B) is J, a heteroatom ancillary ligand σ-bonded to M.
 10. The process of claim 4 wherein M is zirconium or hafnium and L^(B) is independently a substituted or unsubstituted cyclopentadienyl or heterocyclopentadienyl ancillary ligand π-bonded to M.
 11. A continuous process for polymerizing one or more olefin(s) in the presence of a supported composition comprising a transition metal catalyst compound and at least one Lewis acid aluminum compound of the formula:

    R.sub.n Al(ArHal).sub.3-n,

wherein "ArHal" is a halogenated aryl group, n=1 or 2, and R is a monoanionic group other than a halogenated aryl group.
 12. The process of claim 11 wherein the olefin(s) are ethylene or ethylene and one or more olefins having from 3 to 20 carbon atoms.
 13. The process of claim 11 wherein the Lewis acid aluminum compound is supported on an inorganic oxide.
 14. The process of claim 11 wherein the process is a gas phase fluidized bed process. 